RacerZX wrote:So your B-Pipes delete the cats? I live in California, I think such offenses have a mandatory life-sentence here...
I have wondered if there are some V8 Titan headers that could be made to fit

The main cats still exists in the exhaust manifold, in addition to those, 2 more are found in the b-pipes.
Also, check the links again, there are 2 options for the b-pipes from both companies that include cats in the b-pipes and no cats. So, not out of luck there.
The Titan headers do fit, but require a bit of modification to the UCA since the space is tight. That would indeed remove your cats from the exhaust manifold. Doug Thorley long tubes seem to be the best. OBX makes a knock off version for cheaper. There used to be a member on titantalk with a V8 Oathy that had those installed and he did mention some modification to the UCA for them to fit.
As long as your vehicle is at operating temperature, the exhaust reading for emissions should pass. I've got a lot of friends in California that have done the same and pass emissions in other Nissan cars.